1. Field of the Invention
The present invention relates to compressing plates and more particularly but not by way of limitation to a method and apparatus for the use of compressing plates to assist in osteosynthesis.
2. Description of the Related Art
Wire, staple, and plate fixation of bone have been used clinically for decades. In the last 20 years or so, nickel-titanium and shape memory materials have been used in orthopedics for their shape changing and superelastic properties. Shape memory devices feature a martensitic and austenitic form, in which the addition of energy in the form of heat transforms the device from a temporary martensite state to a final austenite state at a defined temperature. The heat for transformation generally is categorized as being (1) room temperature activated (i.e. superelastic), (2) body temperature activated (i.e. body temperature), and (3) above body temperature activated (i.e. heated). The use of a shape memory plate, capable of transforming from a preliminary shape to a compressed final shape, presents unique challenges. If the plate is superelastic, then the plate is inclined to immediately transform at room temperature, making implantation and the use of screws difficult for a surgeon. If the plate is body temperature or heated, then the surgeon has to rely on either body heat, which is reduced during surgery due to the open wound, or an external heating source to transform the plate. For various reasons, many surgeons would prefer a superelastic shape memory plate.
Accordingly, an apparatus and a method of surgical use for a shape memory plate that restrains the plate in an open position while screws are attached and then releases the plate to compress the bones and assist with osteosynthesis would provide an improvement in compressing plate surgeries.